1. Field of the Invention
The present invention relates to a refrigerator, and more particularly, to a refrigerator having a device for opening/closing cool air discharge ports during a defrosting operation and/or when a door is open.
2. Related Art
As shown in FIG. 1, a general refrigerator has a body 14 forming a freezing compartment 15 and a fresh food compartment 1, doors 16 and 12 for opening/closing the freezing compartment 15 and the fresh food compartment 1 respectively, a compressor 19 for compressing refrigerant, an evaporator 11 for generating cool air by evaporating the refrigerant supplied from the compressor 19, and a fan 20 for blowing the cool air generated by the evaporator 11.
A duct member 3 for forming a cool air duct 2 is installed at the rear part of the fresh food compartment 1. The duct member 3 has a plurality of cool air discharge ports 3a opened in the fresh food compartment 1. The cool air blown by the fan 20 flows into the cool air duct 2, and then is discharged into the fresh food compartment 1 through the cool air discharge ports 3a. In the cool air duct 2, a guide device 13 for guiding the cool air flowing into the cool air duct 2 toward the cool air discharge ports 3a is installed.
While the refrigerator operates, frost is generated on the evaporator 11. The cooling efficiency of the evaporator 11 is lowered by the frost. Hence, the refrigerator is equipped with a heater 17 for removing the frost, and performs defrosting operation by heating the evaporator 11 using the heater 17 when the refrigerator is used more than a predetermined period of time.
In such a conventional refrigerator, there is a problem that the heat generated by the heater 17 during the defrosting operation is transmitted into the fresh food compartment 1. The heat generated by the heater 17 is mainly transmitted through the same path with the path for supplying the cool air. That is, the heat is mainly transmitted to the fresh food compartment 1 through the cool air duct 2 and the cool air discharge ports 3a. Due to the heat transmitted to the fresh food compartment 1, the cooling efficiency of the fresh food compartment 1 is lowered, and the status of the food stored therein cannot be maintained properly.
Furthermore, when a user opens the door 12 of the fresh food compartment 1, the outside warm air flows into the fresh food compartment 1, which mainly flows into the area adjacent to the evaporator 11. When the outside air flows toward the evaporator 11, the frost is generated much more on the evaporator 11. Then, the defrosting operation should be performed more frequently. The heater 17 must be operated in order to perform the defrosting operation, so the cooling efficiency is still more lowered by the frequent defrosting.